Sound data processing appartus

ABSTRACT

A sound data processing apparatus includes a central processing unit for controlling predetermined processing in the apparatus, a rewritable RAM, a decoder performing the decoding processing for sound data, and an interface unit for being fitted with an external memory. The sound data processing apparatus reads a driver from the external memory mounted in the interface unit and stores the read driver into the RAM, and reads the sound data from the external memory with the driver and processes the read sound data. As a result, the wastefully using of the memory capacity of the memory mounted in the sound data processing apparatus is reduced.

CROSS-REFERENCE TO RELATED APPLICATION

The entire disclosure of Japanese Patent Application No. 2007-056530filed on Mar. 7, 2007 including the specification, claims, drawings, andabstract is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a sound data processing apparatus forreading sound data stored in an external memory to process the readsound data.

2. Description of the Related Art

In recent years, a sound data processing apparatus for reading sounddata stored in an external memory, such as a flash memory, by connectingthe external memory to the apparatus, and for performing decodingprocessing and the like for the read sound data, has been widely used.

The configuration of a related art sound data processing apparatus 100is shown in FIG. 3. The sound data processing apparatus 100 includes acentral processing unit (CPU) 10, a decoder 12, an interface unit (IFunit) 14, and a NOR-type flash memory 16. A NAND-type external memory102, such as a flash memory, is detected by the CPU 10 by connecting theexternal memory 102 to the IF unit 14.

The CPU 10 reads a driver for accessing the external memory 102, thedriver being stored in the flash memory 16, and accesses the externalmemory 102 by means of the driver. That is, the CPU 10 reads the sounddata stored in the external memory 102 in advance through the IF unit 14on the basis of an instruction by a user or the like, and transfers theread sound data to the decoder 12 at predetermined timing. The decoder12 decodes the sound data transferred from the CPU 10 in accordance witha predetermined format, and outputs the decoded sound data as an audiooutput.

Moreover, the technique of providing an audio system compatible with amulti-codec coping with a plurality of audio codecs was disclosed. Thetechnique was also disclosed that used a CPU to judge whether an audiocodec program stored in a RAM incorporated in a digital signalprocessing unit (DSP) was compatible with music information to bedecoded by the digital signal processing unit or not, and that changedthe processing of the program according to the compatibility.

Now, various types of NAND-type external memories 102 have beendeveloped in recent years. It is necessary to store numerous driverscompatible with respective types of external memories 102 in the flashmemory 16 in advance in order to cope with the various external memories102. The memory capacity of the flash memory 16 should accordingly beenlarged with every increase in the types of external memory 102.

SUMMARY OF THE INVENTION

An aspect of the present invention is a sound data processing apparatus,including: a rewritable first memory; a decoder for performing sounddata decoding processing; an interface unit connected to a second memorystoring the sound data and a driver; a read only third memory forstoring a boot program executed for reading the driver from the secondmemory connected to the interface unit and storing the read driver intothe first memory; and a central processing unit for controllingprocessing of the first memory, the third memory, the decoder, and theinterface unit, wherein the central processing unit performs control soas to read the driver from the second memory connected to the interfaceunit based on the boot program and storing the read driver into thefirst memory, to read the sound data from the second memory connected tothe interface unit by means of the driver stored in the first memory,and to transfer the read sound data to the decoder.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention will be described indetail based on the following drawings, wherein:

FIG. 1 is a block diagram showing the configuration of a sound dataprocessing apparatus of an embodiment of the present invention;

FIG. 2 is a flow chart showing a processing method of the sound dataprocessing apparatus of the embodiment of the present invention; and

FIG. 3 is a block diagram showing the configuration of a related artsound data processing apparatus.

DESCRIPTION OF PREFERRED EMBODIMENTS

[Configuration of Apparatus]

A sound data processing apparatus 200 of an embodiment of the presentinvention is composed of a central processing unit (CPU) 20, a decoder22, an interface unit (IF unit) 24, a volatile memory (RAM) 26, and anonvolatile memory (ROM) 28, as shown in FIG. 1.

The CPU 20, the decoder 22, the IF unit 24, the RAM 26, and the ROM 28are connected with one another through a bus so as to be able tomutually exchange data. The sound data processing apparatus 200 isconnected to an external memory 102 through the IF unit 24. A memorychip, such as a flash memory, and a memory card can be used as theexternal memory 102.

The CPU 20 is a semiconductor device to generally control a piece ofelectronic equipment including the sound data processing apparatus 200.As the electronic equipment to be mounted with the sound data processingapparatus 200, for example, a cellular phone equipped with wirelesscommunication means, a portable music reproducing apparatus, and apersonal digital assistant (PDA) for performing data management can becited. The CPU 20 can be constituted by, for example, an applicationspecific integrated circuit (ASIC). The CPU 20 controls the electronicequipment by accessing a boot program and a library, both stored in theROM 28. For example, if the sound data processing apparatus 200 is thecellular phone, then the CPU 20 accepts the key input of a user from anoperation unit (not shown) connected to the bus, and controls theprocessing of the wireless transmission and reception of sound signalsand electronic mail according to the key input.

Incidentally, the present embodiment has a feature of sound dataprocessing in which the sound data stored in the external memory 102 isread to be processed, but the control of the processing will bedescribed later.

The decoder 22 takes in the sound data subjected to coding processingand compressing processing in a predetermined format from the bus, andperforms the expanding processing and the decoding processing of thesound data in accordance with the format. As the coding system of sounddata, for example, WMA, AMR, Div X, G.723, and MP3 can be cited.

The IF unit 24 is composed of an adapter unit mounting the externalmemory 102 therein, a connector unit electrically connected with anexternal terminal of the external memory 102, and a data processing unitperforming the reading and the writing of data with the external memory102.

The adapter unit of the IF unit 24 is configured to have an insertionspace adjusted to the external form of the external memory 102. Theconnector unit of the IF unit 24 touches an electrode provided on theexternal memory 102 when the external memory 102 is mounted in theadapter unit, and as a result the connector unit electrically connectsthe internal electric circuits of the external memory 102 with the dataprocessing unit of the IF unit 24.

The external memory 102 stores a primitive driver necessary for thesound data processing apparatus 200 to access the external memory 102,and an application program necessary for the sound data processingapparatus 200 to perform processing for music data reproduction and thelike. If the external memory 102 is a memory card, for example, acontrol program or a control logic circuit in the data processing unitof the IF unit 24 interprets an instruction for data reading and thelike from the CPU 20 through a register in conformity with a PC card ATAstandard interface, and converts the instruction into a commandaccording to the type of external memory 102 mounted on the adapterunit. The command is transmitted to the internal electric circuits ofthe external memory 102, and the data (sound data) stored in theexternal memory 102 is read.

Incidentally, the sound data processing apparatus 200 performs theprocessing, such as music data reproduction, by means of the applicationprogram stored in the external memory 102 and a basic program, whichwill be described later, stored in the ROM 28. Because the externalmemory 102 is a rewritable memory, a developer can rewrite theapplication program to update the program, or correct bugs. That is, itis preferable to use a program that is capable of being rewritten as theapplication program stored in the external memory 102.

The RAM 26 is a volatile semiconductor memory. As the RAM 26, an SRAMcan be used. The primitive driver and the application program, both readfrom the external memory 102, are expanded in the RAM 26, and aresubjected to processing according to each program by the CPU 20.

The ROM 28 is a nonvolatile semiconductor memory. The ROM 28 stores aboot program for automatically performing a series of processing stepsat the time of starting the access to the external memory 102, a libraryto be used by the driver of the external memory 102, and the basicprogram necessary for operating the sound data processing apparatus 200.

Incidentally, only the library commonly referred to by each driver foreach of a plurality of types of external memories 102 is stored in theROM 28. That is, a library particularly referred to by each driver isnot stored in the ROM 28. Moreover, it is preferable to uses a programhaving no possibility of being rewritten as the basic program stored inthe ROM 28. This prevents wastefully using up the the memory capacity ofthe ROM 28.

[Control Method]

Next, the control of the sound data processing apparatus 200 of thepresent embodiment will be described with reference to the flow chartshown in FIG. 2.

At Step S10, the external memory 102 is detected by the CPU 20. When theexternal memory 102 is mounted on the IF unit 24, the CPU 20 iselectrically connected to the external memory 102 through the IF unit24. By always outputting a signal o allow the CPU 20 to detect themounting of the external memory 102 into the IF unit 24, the electricalconnection of the IF unit 24 with the external memory 102 can bedetected.

At Step S12, the primitive driver is read from the external memory 102in accordance with the boot program. When the external memory 102 isdetected by the CPU 20 at Step S10, the CPU 20 reads a program called aninitial program loader (IPL), which is previously stored in the ROM 28.By executing the IPL, the CPU 20 invokes the boot program recorded in anarea called a boot sector of the area called a master boot record (MBR)of the ROM 28.

The boot program is a program for reading the primitive driver stored inthe external memory 102. The primitive driver is stored in common memoryspaces in various types of the external memories 102. The CPU 20accesses the predetermined memory space of the external memory 102 andreads the stored primitive driver to store the read primitive driverinto the RAM 26 in accordance with the boot program.

Moreover, if there is information, such as the library, peculiar to theprimitive driver, then it is preferable to store also this informationinto the external memory 102 in advance, and to read the informationtogether with the primitive driver and store them in the RAM 26.

At Step S14, the application program is read from the external memory102 to be expanded in the RAM 26, and an instruction of the reproductionprocessing of sound data is accepted on the basis of the basic programstored in the ROM 28 and the application program expanded in the RAM 26.The CPU 20 accepts a sound data reproduction processing instructionthrough a user interface (not shown), such as the operation unit, andspecifying information for specifying the sound data of a readingobject. The specifying information is, for example, a file name or thelike that is specifically added to the sound data. Moreover, the sounddata processing apparatus 200 may be adapted so that the CPU 20 maydisplay a file name list of sound data that has been previously readfrom the external memory 102 mounted in the IF unit 24 on the displayunit (not shown) of the user interface, to allow a user to select thefile name of the sound data of the reproduction object in the list.

At Step S16, the CPU 20 accesses the external memory 102 in accordancewith the read primitive driver, and performs the reproduction processingfor the sound data. The CPU 20 accesses the header area in which theinformation expressing the memory area storing each sound data thereinis registered by means of the primitive driver stored in the RAM 26 atStep S12, and ascertains the starting address and the ending address ofthe memory area in which the sound data specified by the specifyinginformation input at Step S14 is stored. The CPU 20 then sequentiallyreads the data from the starting address to the ending address, andtransmits the read data to the decoder 12. When the decoder 12 receivesthe transmitted sound data, the decoder 12 decodes the sound data andconverts it into an audio signal in accordance with the format of thesound data, and outputs the converted sound signal.

Incidentally, if it is necessary for the primitive driver to refer to alibrary, it is preferable for the primitive driver to perform theprocessing, referring to the library stored in the RAM 26 or the ROM 28.That is, because the library commonly referred to by a plurality ofdrivers is previously stored in the ROM 28, the primitive driver canrefer to the library. Moreover, because the library specific to aprimitive driver has been read from the external memory 102 at Step S12to be stored in the RAM 26, the primitive driver can refer to thelibrary in the RAM 26.

As described above, the present embodiment reads the primitive driverstored in the external memory 102 and stores the read primitive driverinto the built-in memory, and accesses the external memory 102 on thebasis of the primitive driver. It therefore becomes unnecessary to storenumerous drivers in the sound data processing apparatus 200 in advance.Consequently, the memory capacity of the built-in memory can be reducedin comparison with that of the related art.

Moreover, the present embodiment is configured to store the bootprogram, the library, and the basic program in the ROM 28, and to storethe primitive driver and the application program in the external memory102. Because some of the programs are transformed as library and storedin the ROM 28, the size of the programs stored in the external memory102 can be reduced. Therefore the storage capacity of the RAM 26, inwhich the programs stored in the external memory 102 are expanded, canbe reduced so that the circuit size can be reduced. If the ROM 28 ismade of a mask ROM and the RAM 26 is made of an SRAM, the mask ROM canmake the circuit size thereof smaller than that of the SRAM.Consequently, the circuit size of the sound data processing apparatus200 can be reduced more in comparison with that in the case of storingall the programs in the external memory 102. Because the programs havingthe possibility of being rewritten are stored in the external memory102, it is possible to rewrite the programs for updating the programs orfor correcting bugs.

What is claimed is:
 1. A sound data processing apparatus, comprising: afirst memory, that is rewritable; a decoder for performing decodingprocessing for sound data; an interface unit connected to a secondmemory storing the sound data and an interface driver for reading outthe sound data, the second memory being an external memory; a thirdmemory, that is read only memory, storing a boot program executed forreading the interface driver from the second memory connected to theinterface unit and storing the read interface driver into the firstmemory; and a central processing unit for controlling processing of thefirst memory, the third memory, the decoder, and the interface unit,wherein the central processing unit performs control so as to read theinterface driver from the external memory connected to the interfaceunit based on the boot program and store the interface driver into thefirst memory, read the sound data from the second memory connected tothe interface unit by means of the interface driver stored in the firstmemory, and transfer the read sound data to the decoder.
 2. The sounddata processing apparatus according to claim 1, wherein the secondmemory stores an application program for performing reproductionprocessing for the sound data, and the third memory stores a basicprogram for performing the reproduction processing for the sound data.3. The sound data processing apparatus according to claim 1, wherein thefirst memory is an SRAM, and the third memory is a mask ROM.
 4. Thesound data processing apparatus according to claim 2, wherein the firstmemory is an SRAM, and the third memory is a mask ROM.